How do you graph #y=cos4x#?

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Answer 1 · 2016-09-30T11:46:54

The period of the cosine wave y = cos kx = #2/kpi#.

Here, for y = cos 4x, the period is #(2pi)/4=pi/2#

Let us make a Table, with spacing #pi/16#.

for one period #x in [0, pi/2]#

#(x, y): (0, 1) (pi/16, 1/sqrt 2) (pi/8, 0), (3/16pi, -1/sqrt 2) (pi/4, -1)#

#(5/16pi,. -1/sqrt 2) (3/8pi, 0) (7/16pi, 1/sqrt 2) (pi/2, 1)#

The graph for this Table will show one full wave.

Foe successive periods, move this graph laterally ( in the x-

direction), through #pi/2 =1.57# units..